How should I ask her out if this is all I have?

So I was was going to ask my friends thoughts on asking this girl out. But I kinda have a feeling that she will tell me not to. It can hurt to try and you never know until you do try. But how would I ask this girl out if all I have is her snapchat. We snapchat every now and then during the day. When we hang out we talk and she is giving me signs that she is interested. So how would you go about asking her out?